Capsule friendly tips for phacoemulsification and for irrigation / aspiration

ABSTRACT

A surgical tool that includes a tip with a smooth, rounded edges and free of any sharp edges. The tip may have pores on its top, but none on the underside of its base. The distal end may have an open port with micro wires that form a Maltese cross shape. The distal end may be instead closed with protrusions spaced from each other by gaps or recesses.

CROSS-REFERENCE TO COPENDING PATENT APPLICATIONS

The present application is a continuation-in-part utility patentapplication from U.S. utility patent application Ser. No. 12/794,715filed Jun. 4, 2010, now U.S. Pat. No. 8,398,578 issued Mar. 19, 2013,which in turn claims the benefit of priority from U.S. provisionalpatent application Ser. No. 61/184,399 filed Jun. 5, 2009.

BACKGROUND OF THE INVENTION

1. Field of the Invention

One aspect of the invention relates to surgical tools in the form of anelongated shaft and tip suited for use in phacoemulsification surgicalinstruments and irrigation-aspiration instruments.

2. Discussion of Related Art

Conventional phacoemulsification tips are sharp and have an overly largeport that admits the eye capsule in a blink-of-an-eye. The eye capsule,when sucked into the overly large port, puckers and rips to producerapidly widening tear lines through which vitreous prolapses, whichoften leads to vitreous loss. Therefore, the use of such conventionalphacoemulsification tips that are sharp with the overly large port runthe risk of causing capsule ruptures, which is a very seriousintraoperaive, i.e., surgical, complication. As an alternative, femtolasers are used (sometimes referred to as femtosecond lasers) to assistcataract surgery procedures.

In an article entitled “Femtosecond Laser Cataract Surgery: AdvantagesAwait Clinical Trial Results” by James Brice and published Nov. 26,2012, Femtosecond laser cataract surgery are discussed. Excerpts fromthe article are in the following seven paragraphs.

Femtosecond lasers promise to literally to cut a new edge in terms ofthe precision and accuracy of incisions made during cataract surgery,according to Calvin Roberts, MD, chief medical officer of Bausch+Lomb.Bausch+Lomb is 1 of 5 companies that produce US Food and DrugAdministration-cleared femtosecond laser surgical systems.

Surgery using handheld instruments is the current standard for treatingcataracts, which are responsible for nearly 50% of blindness worldwide.The success of this approach depends to a great extent on the surgeon'sskill and experience. About 10 million cataract surgeries are performedannually worldwide, according to the World Health Organization. Many ofthose patients could benefit from a conversion to femtosecond lasersguided by ultra-high-resolution 3-dimensional optical coherencetomography (OCT).

Femtosecond lasers are well suited for cataract surgery because of theirability to tightly focus energy to produce precise surgical incisions,Dr. Roberts said. Cuts of a uniform depth into the lens are possible.The disruptive heat associated with current laser technology is reducedas the laser pulses once every one-trillionth of a second. The abilityto focus such energy allows the surgeon to cut deeply on a single planewithout collateral damage, he said.

Results of preliminary research are promising. Femtosecond lasersproduce continuous anterior incisions for capsulorrhexis that are twiceas strong and more than 5 times as precise in size and shape as manualincisions, according a 2010 study by Palanker and colleagues at StanfordUniversity School of Medicine, Stanford, Calif.

Palanker and colleagues' research revealed that segmenting and softeningthe lens with a femtosecond laser simplifies its emulsification andremoval. Three-dimensional cutting of the cornea takes advantage ofinternal pressure in the eye to create self-sealing incisions, and itallows exact placement of the limbal-relaxing incisions, often performedin the same procedure, that are used to treat astigmatism.

Friedman and colleagues, also at Stanford University School of Medicine,measured the accuracy of an OCT-guided femtosecond laser for cuttingspecified circles and curved incisions and compared it with manuallycreated capsulorhexis in a small human study. Deviation from theintended diameter of the resected capsule disk was 29 (±26 μm) for thelaser technique and 337 μm (±258 μm) for manual incisions. Meandeviations from circularity were 6% for the laser and 20% for manualincisions.

The advantage conferred by this precision can be applied to cornealincisions, anterior capsulotomy, and lens softening and fragmentationbefore aspiration, noted Roger F. Steinert, MD, chair of ophthalmologyat the University of California, Irvine, School of Medicine. “You can'tdo these things repeatedly or dependably when you are operating manuallywith a blade,” he said.

Indeed, the safety benefits of femtosecond laser-assisted cataractsurgery are mentioned in a further article entitled “Technique yieldssafety benefits Femtosecond laser-assisted cataract study procedureminimizes corneal trauma” by Cheryl Guttman Krader, reviewed by Zoltan ZNagy, MD, PhD, and published in Opthalmology Times on Dec. 1, 2012. Thearticle mentions that the increased safety of the femto[second] laserprocedure in this study might be attributed to the user of lessultrasound energy during phacoemulsification and was associated withless early corneal edema and better corneal endothelial cell functioncompared with standard cataract surgery. Average phaco power was reducedby as much as 51% compared to standard cataract surgery and theeffective phaco time was reduced by as much as 43% compared to standardcataract surgery.

An intraocular lens, or IOL, is an artificial lens made of plastic,silicone or acrylic that performs the function of the eye's naturallens. Most of today's IOLs are less than a quarter of an inch indiameter and soft enough to be folded so they can be placed into the eyethrough a very small incision.

There is a need to reduce a risk of causing capsule ruptures, i.e., byavoiding the use of conventional phacoemulsification tips that are sharpand that have an overly large port. That is, there is a need forphacoemulsification tips that are safe in the sense that they are not aslikely to cause capsule ruptures. That is, the surgical tool should be“capsule friendly” to lessen the likelihood of creating capsule rupturesduring their use in phacoemulsification surgical procedures or inirrigation-aspiration applications of the eye.

There is also a need to score and break-up glossy, coagulated walls,whose glossy, coagulated state resulted from impingement by a laserenergy beam during the course of Femtosecond laser-assisted cataractsurgery.

SUMMARY OF THE INVENTION

One aspect of the invention resides in “capsule friendly” tips suitedfor use with phacoemulsification type machines and withaspiration-irrigation instruments. Such “capsule friendly” tips achievesafe removal of cataract fractions without sucking in iris tissue orpulling in and thus rupturing the capsule. The “capsule friendly” tipsare constructed so only the aspiration of soft cortex occurs whileirrigating the area.

One embodiment resides in a mulberry tip that has protrusions configuredto collectively and cooperatively engage with epinucleus corticalmaterial so as, under manual pressure and guidance, to divide corticalfibers of the epinucleus cortical material. The mulberry tip beingsecured to a hollow shaft of an aspiration-irrigation tool in anairtight manner that is sufficiently tight for a suction force impartedinto the hollow of the hollow shaft to suck the divided cortical fibersinto the port and then flow through the hollow of the base to reach thehollow of the hollow shaft. Neighboring ones of the protrusions areseparated from each other by gaps or recesses. Each of the protrusionshave curved external surfaces entirely free of sharp edges. Both thehollow shaft and the hollow base are constructed of materials sufficientto avoid their collapse upon being subjected to the suction force thatis of a magnitude necessary for the divided cortical fibers to suck intothe port.

Still another embodiment resides in a hollow tip having a base thatextends between proximal and distal ends, with the distal endterminating into a port crossed by micro wires in a shape of a Maltesecross. The proximal end is configured to fit to a hollow shaft in anairtight manner. The airtight manner is sufficiently tight for a suctionforce imparted into the hollow of the hollow shaft to suck dividedcortical fibers of an epinucleus cortical material into the open portabout the micro wires and then flow through the hollow of the base toreach the hollow of the hollow shaft. Both the hollow shaft and thehollow base are constructed of materials sufficient to avoid theircollapse upon being subjected to the suction force that is of amagnitude necessary for the divided cortical fibers to suck into theopen port around the micro wires.

BRIEF DESCRIPTION OF THE DRAWING

For a better understanding of the present invention, reference is madeto the following description and accompanying drawings, while the scopeof the invention is set forth in the appended claims.

FIG. 1 is an isometric view of a funnel style kugeln tip embodiment inaccordance with the invention in which an irrigation/aspiration shaft orneedle curves to terminate into a funnel shape with pores directedbackward to constitute a distal tip of an irrigation/aspiration surgicalhand piece.

FIG. 2 is an isometric view of a horseshoe style kugeln tip embodimentin accordance with the invention in which an irrigation/aspiration shaftor needle curves to terminate into a horseshoe shape with pores directedbackward to constitute a distal tip of an irrigation/aspiration surgicalhand piece.

FIG. 3 is an isometric view of an oblong “Retro” style kugeln tipembodiment in accordance with the invention with longer backward reachin which an irrigation/aspiration shaft or needle curves to terminateinto a oblong shape with pores directed backward to constitute a distaltip of an irrigation/aspiration surgical hand piece.

FIG. 4 is an isometric end view of a cross-bun or Maltese cross tipembodiment in accordance with the invention.

FIG. 5 is an isometric side view of a cross-bun or Maltese cross tipembodiment in accordance with FIG. 4.

FIG. 6 is an isometric view of a mulberry tip in accordance with astraight shaft embodiment of the present invention.

FIG. 7 is an isometric view of a mulberry tip in accordance with anindented shaft embodiment of the present invention.

FIG. 8 is an isometric view of a conventional regular, roundedphacoemulsification tip.

FIG. 9 is an isometric view of a cataract with the nucleus of the lensbeing broken up by energy delivered by a laser beam in accordance withconventional techniques.

FIG. 10 is an isometric view of a conventional smooth, rounded tiphaving difficulty getting across a tissue peripheral wall (peripheralwall arising from the peripheral effect of an laser energy beam ontissue) in an effort to enter soft cortex for the purpose of aspirating.

FIG. 11 is an isometric view of a Mulberry tip in accordance with theinvention breaking up a tissue peripheral wall (the tissue peripheralwall arising from the peripheral effect an laser energy beam on tissue)that can be pushed more easily than the smooth, rounded tip of FIG. 10into the soft tissue of the cortex to start aspirating.

FIGS. 12-13 are isometric views of side-by-side comparison of theMulberry tip aspiration/irrigation tool of FIG. 11 and the conventionalsmooth, rounded tip aspiration/irrigation tool of FIG. 10.

DETAILED DESCRIPTION OF THE INVENTION

The tips of each of the embodiments include surgical hand piece tipsthat are suited for ultrasonic phacoemulsification (U-Phaco) typeapplications, irrigation/aspiration (I/A) type applications or bothtypes of applications.

Kugeln Tip 60, 62, 64

Turning to FIGS. 1-3, kugeln tips in accordance with differentembodiments of the invention are shown each with a face with poresdirected backward toward the surgeon to facilitate the removal ofhard-to-get cortex under the port of entry, which is usually the 12o'clock cortex.

In the case of FIG. 1, a funnel type kugeln tip is shown having acircular disc shaped globe 60 and an irrigation/aspiration shaft orneedle 66 that extends within an infusion sleeve 16. The shaft or needle66 terminates into a funnel shape that diverges at a transition into aface of the circular disc shaped globe 60. The pores 68 are directedbackward and arranged in the face of the circular disc shaped globe 60on the same side of the circular disc shaped globe 60 where the shaft orneedle 66 funnels into the circular disc shaped globe 60. There are nopores on the opposite side of the circular disc shape globe 60.

In the case of FIG. 2, a horseshoe style kugeln tip is shown with ahorseshoe shaped globe 62 and an irrigation/aspiration shaft or needle66 that extends within an infusion sleeve 16. The shaft or needle 66terminates into the horseshoe shaped globe 62. The pores 68 are directedbackward in the horseshoe shaped globe 62 on the same side of thehorseshoe shaped globe 62 from which approaches the shaft or needle 66to reach the horseshoe shaped globe 62. There are no pores on theopposite side of the horseshoe shaped globe 62.

In the case of FIG. 3, an oblong “Retro” style kugeln is shown having anoblong globe 64 with a longer backward reach that in the case of theembodiments of FIGS. 1 and 2. The irrigation/aspiration shaft or needle66 of FIG. 3 extends within an infusion sleeve 16 and terminates intothe oblong globe 64. The oblong globe 64 has pores 68 that are directedbackward on the same side of the oblong globe 64 that the shaft orneedle 66 reaches the oblong globe 64. There are no pores on theopposite side of the oblong globe 64.

Turning to FIGS. 4-5, the cross-bun or Maltese cross guard tips 80resemble conventional U-Phaco and I/A tips the most out of all theembodiments and thus are likely the easiest to retool an existing tipmanufacturing facility and thus the easiest for a conventional tipmanufacturer to produce. Both U-Phaco and I/A type cross-bun or Maltesecross guard tips 80 look somewhat alike in that the aspiration port ofeach is located dead front and each has a built-in guard that is allone-piece with the tip.

The globe of the tip of the cross-bun or Maltese cross type isconstituted by a hollow base 86 the extends between proximal and distalends with two wire arms 82 made of fine smooth micro wires that straddlecrosswise the port 84 at the distal end of the hollow base 86. Theyminimally bulge to appear slightly rounded and not sharp and connect tothe edges of the port widened a bit, as if in shape of a Maltese cross.The two wire arms 82 cross at 90 degrees across the port 84, therebydividing the port 84 into four smaller entrances that are each too smallfor the capsule to enter. The emulsified matter, however, flow fasteraround the wires, but then quickly join together to flow the full sizedchannel downstream of the wire part of he port to continue to beaspirated in accordance with the flow dynamics of conventional tips.This cross-bun or Maltese cross type of tip may be considered that of ashaft tip with the aspiration prevented by wire guards from sucking inthe capsule and iris.

The proximal end of the cross-bun or Maltese cross type tip isconfigured to fit to a hollow shaft in an airtight manner. The airtightmanner is sufficiently tight for a suction force imparted into thehollow of the hollow shaft to suck divided cortical fibers of anepinucleus cortical material into the open distal end around the microwires and then flow through the hollow of the base to reach the hollowof the hollow shaft. Both the hollow shaft and the hollow base areconstructed of materials sufficient to avoid their collapse upon beingsubjected to the suction force that is of a magnitude necessary for thedivided cortical fibers to suck into the open distal end around themicro wires.

Turning to FIGS. 6 and 7, two types of mulberry tips 90, 92 are shown,i.e., FIG. 7 is for a straight phaceoemuslfication shaft and FIG. 8 isfor an indented phacoemulsification shaft. The size of the shaft foreach type of mulberry tip 90, 92 is the same as that of a shaft of aconventional phacoemulsification rounded tip 100 of FIG. 9. Theconventional phacoemulsification rounded tip 100 in this example has anend that is to smooth and thus just compresses the cortex material toshrivel it up so it could be aspirated better.

Each mulberry tip 90, 92 has a respective rounded surfacew protrustions94, 96 separated from each other by gaps or recesses 95. The roundedsurface protrusions 94, 96 are configured to engage epinucleus corticalmaterial to work as a “battering ram” to divide cortical fibers so theycan become dislodged and be aspirated with more ease than forconventional aspiration/irrigation tips 100 of FIG. 9. For instance, therounded surface protrusions 94, 96 may take the form of a plurality ofrounded protrusions that extend in a direction of elongation of theshaft (from which the mulberry tip extends). The rounded protrusions maybe arranged concentric with a center axis of the tip and may be arrangedin a symmetrical manner.

Further, there is a suction port 98 (hole, port or opening) foraspiration that should be sized to prevent sucking in the capsule duringaspiration. The smooth, rounded surfaces of the tips form no regions ofsharpness that might otherwise cut into the capsule during aspiration.For instance, there are intersecting planar surfaces in such smooth,rounded surfaces of the tips.

The mulberry tip 90, 92 of the present invention is fitted onto a hollowaspiration tube 112 of a conventional aspiration-irrigation instrumentor handpiece for removal of the cortex through aspiration, which removalmay or may not be in conjunction with Femto[second] laser-assistedcataract surgery.

The Femto laser is operated to chop or cut the cortex as shown in FIG. 9and subsequently aspiration is carried out via a suction port 98 toremove the cortex. The mulberry tip 90, 92 used in the manner of FIG. 11disrupts soft cortical material better than can be done for smoothly,rounded conventional aspiration/irrigation tips 100 used in the mannerof FIG. 10. A side-by-side comparison of the surgical tools of FIGS. 10and 11 are set forth in FIGS. 12 and 13.

Initially, a Femto laser beam creates a circular opening in the anteriorcapsule of the cataract. This circular opening is defined by an edge 104of the capsule following previous capsularhesis (see FIG. 9).

The Femto laser beam 102 is then directed to scan a grid pattern as itpasses through the circular opening defined by the edge 104 to core outthe cataract contents 106 contained within the capsular bag and chopsthe cataract contents 106 (that constitutes the nucleus of the cataract)into chunky pieces 110 of fragmented, deconstructed nucleus) but leavesa smooth, peripheral wall 108 that is more viscous than the softer,adjacent cortical tissue. The smooth, peripheral wall 108 borders aroundthe outer periphery of the energy beam from the laser and lies adjacentto softer, cortical tissue that beyond the smooth, peripheral wall.Indeed, the smooth, peripheral wall is in a somewhat glossy, coagulatedstate and may be considered an interface constituted by a cylindricalzone of coagulative remnants of cortical material. One might analogizethe effect of the laser beam going through the cataract tissue with thatof a pineapple core: the laser beam cubes the nucleus into small piecesbut leaves the smooth, peripheral wall somewhat coagulated.

Turning to FIG. 10, a conventional aspiration-irrigation tool is shownhaving a conventional, smooth rounded tip 100 whose proximal end issecured to a distal end of an aspiration tube 112 in any conventionalmanner (such as with engaging screw threads or friction fit). One canappreciate that the rounded distal end of the conventional smooth,rounded tip 100 renders it difficult for it to grasp the cortex whenbrought into contact with the wall of the smooth cylinder.

In a conventional manner, suction is imparted to the hollow tube 112 tosuck in cut tissue through the suction port 98. In a conventionalmanner, the proximal end of the smooth rounded tip 100 is secured to adistal end of a hollow aspiration tube 112, such as with engaging screwthreads or is friction fit as the case may be. There is also asurrounding concentric sleeve 16 for irrigating the region in the eyewhile aspiration is being carried out by directing irrigation fluid toflow in the space between the inner surface of the surroundingconcentric sleeve 16 the outer surface of the hollow aspiration shaft112.

Turning to FIG. 11, the mulberry tip 90, 92 of the present invention hasno sharp edges—just rounded, surface protrusions 94, 96 separated fromeach other by gaps or recesses. In a conventional manner, the proximalend of the mulberry tip 90, 92 is secured to a distal end of a hollowaspiration tube 112, such as with engaging screw threads or friction fitas the case may be. There is also a surrounding concentric sleeve 16 forirrigating the region in the eye while aspiration is being carried outby directing irrigation fluid to flow in the space between the innersurface of the surrounding concentric sleeve 16 the outer surface of thehollow aspiration shaft 112.

Under manual force of sufficient magnitude being imparted to themulberry tip 90, 92, the mulberry tip 90, 92 is urged against a smooth,peripheral wall 108 to wedge cortical tissue of the smooth, peripheralwall 108 into the gaps or recesses that are between neighboring ones ofthe rounded, surface protrusions 94, 96. The mulberry tip 90, 92 readilyand easily scores and breaks up the smooth, peripheral wall 108 intocrumbled, cortical pieces 114 by virtue of the collective action of therounded surface protrusions 94, 96 that are separated from each other bythe gaps or recesses (in effect defining indentations betweenneighboring ones of the rounded, surface protrusions 94, 96).

The rounded, surface protrusions 94, 96 resemble a cobblestone layoutwhen viewed from the front end so they can wedge in and loosen cortextissue that is of a consistency of cream cheese (or in any event moreviscous than the adjacent, softer cortex tissue). The loosened cortextissue is then aspirated into the suction port 98 to enter and passthrough the base tube and to reach the hollow aspiration tube 112. Thebase tube lies between the surface port 98 and the hollow aspirationtube 112 and is in the vicinity of where the reference line for 90, 92touches in FIG. 11.

The soft, fluffy cortex can then right away be sucked into the suctionport 98 and thus be removed—in effect speeding up the cortical removaltime over that where the conventional smoothly, rounded tip design isused. Indeed, the protrusions are configured, by virtue of their roundedsurfaces separated from each other by gaps or recesses 95, tocollectively and cooperatively engage with epinucleus cortical materialunder manual pressure and guidance to divide cortical fibers of theepinucleus cortical material.

The mulberry tip 90, 92 has a base tube and is elongated betweenproximal and distal ends and has the suction port 98 spaced from theproximal and distal ends. However, the base tube is hollow from the portto the proximal end, but need not be hollow all the way to the distalend. Indeed, the protrusions are arranged at the distal end.

The proximal end connects to the hollow shaft 112 in an airtight mannersufficient to enable a suction force, which is imparted within thehollow shaft 112, to suck divided cortical fibers of epinucleus corticalmaterial into the port and thereafter flow through the hollow of themulberry tip 90, 92 to enter the hollow of the hollow shaft.

Both the hollow shaft 112 and the hollow base (between the suction port98 and the proximal end) are constructed of materials sufficient toavoid collapsing (that would impede or block suction) upon beingsubjected to the suction force that is of a magnitude necessary for thedivided cortical fibers to suck into the port and thereafter flowthrough the hollow of the mulberry tip 90, 92 to enter the hollow of thehollow shaft.

Any of the “capsule friendly” tips as depicted in all the embodiments ofthe present invention may be used as the irrigation-aspiration tips forall models and makes of conventional irrigation-aspiration handpiecesutilizing in phacoemulsification consoles by conventional manufacturers.The choice of material for the “capsule friendly” tips of any of theembodiments of the present invention may include that of metal orhardened silicone.

While the foregoing description and drawings represent the preferredembodiments of the present invention, it will be understood that variouschanges and modifications may be made without departing from the scopeof the present invention.

What is claimed is:
 1. A capsule friendly surgical tool, comprising atip having proximal and distal ends with a hollow base extending betweenthe proximal end of the tip and a suction port, the tip having aplurality of protrusions at the distal end of the tip each separatedfrom each other by gaps or recesses of dimensions sufficient to wedge inand loosen cortex tissue in response to sufficient manual force beingimparted to the tip, each of the protrusions having curved externalsurfaces entirely free of sharp edges, both the hollow base and thesuction port being spaced from the distal end of the tip, the proximalend of the tip being configured to fit to a hollow shaft in an airtightmanner sufficient for a suction force imparted into the hollow of thehollow shaft to suck divided cortical fibers of an epinucleus corticalmaterial into the suction port to flow through the hollow of the hollowbase to reach the hollow of the hollow shaft, the protrusions beingconfigured to collectively and cooperatively engage with the epinucleuscortical material to, under manual pressure and guidance, divide thecortical fibers of the epinucleus cortical material, both the hollowshaft and the hollow base being constructed of materials sufficient toavoid their collapse upon being subjected to the suction force that isof a magnitude necessary for the divided cortical fibers to suck intothe suction port to reach the hollow of the hollow shaft via the hollowof the hollow base.
 2. The capsule friendly surgical tool of claim 1,wherein the base extends between the proximal and distal ends of the tipuniformly about a centerline passing through a hollow of the base, theprotrusions being configured in a manner symmetric with each other andconcentric with the centerline.
 3. The capsule friendly surgical tool ofclaim 1, wherein each of the protrusions has rounded surfaces.
 4. Amethod of operating a capsule friendly surgical tool, comprisingproviding a tip having proximal and distal ends, the tip having a hollowbase that is hollow and extends from the proximal end of the tip to asuction port, the tip having a plurality of protrusions at the distalend of the tip each separated from each other by gaps or recesses ofsufficient dimension to wedge in and loosen cortex tissue in response toapplication of sufficient manual force imparted to the tip, each of theprotrusions having curved external surfaces entirely free of sharpedges, both the hollow base and the suction port being spaced from thedistal end of the tip, the proximal end of the tip being configured tofit to a hollow shaft that is hollow in an airtight manner sufficientfor a suction force imparted into the hollow of the hollow shaft to suckdivided cortical fibers of an epinucleus cortical material into thesuction port to flow through the hollow of the hollow base to reach thehollow of the hollow shaft, fitting the proximal end of the tip to thehollow shaft in the airtight manner; and collectively and cooperativelyengaging the protrusions, under manual pressure and guidance, with theepinucleus cortical material to divide cortical fibers of the epinucleuscortical material, both the hollow shaft and the hollow base beingconstructed of materials sufficient to avoid their collapse upon beingsubjected to the suction force that is of a magnitude necessary for thedivided cortical fibers to suck into the suction port to reach thehollow of the hollow shaft via the hollow base.